/* APHI Main Stylesheet */
/* Professional, clean design for Artificial Public Health Intelligence */

/* ============================================
   CSS Variables & Design System
   ============================================ */
:root {
  /* Primary Colors */
  --aphi-royal-blue: #0047AB;
  --aphi-deep-blue: #003580;
  --aphi-light-blue: #4A90E2;
  --aphi-sky-blue: #E8F4F8;

  /* Neutral Colors */
  --aphi-white: #FFFFFF;
  --aphi-off-white: #F9FAFB;
  --aphi-light-gray: #E5E7EB;
  --aphi-gray: #6B7280;
  --aphi-dark-gray: #374151;
  --aphi-charcoal: #1F2937;
  --aphi-black: #111827;

  /* Accent Colors */
  --aphi-green: #10B981;
  --aphi-orange: #F59E0B;
  --aphi-red: #EF4444;

  /* Typography */
  --font-primary: 'Inter', -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, sans-serif;
  --font-heading: 'Orbitron', 'Inter', sans-serif;

  /* Spacing */
  --spacing-xs: 0.5rem;
  --spacing-sm: 1rem;
  --spacing-md: 1.5rem;
  --spacing-lg: 2rem;
  --spacing-xl: 3rem;
  --spacing-2xl: 4rem;

  /* Transitions */
  --transition-fast: 0.15s ease;
  --transition-normal: 0.3s ease;
  --transition-slow: 0.5s ease;
}

/* ============================================
   Reset & Base Styles
   ============================================ */
* {
  margin: 0;
  padding: 0;
  box-sizing: border-box;
}

html {
  scroll-behavior: smooth;
  font-size: 16px;
}

body {
  font-family: var(--font-primary);
  color: var(--aphi-charcoal);
  background-color: var(--aphi-white);
  line-height: 1.6;
  -webkit-font-smoothing: antialiased;
  -moz-osx-font-smoothing: grayscale;
}

/* ============================================
   Accessibility
   ============================================ */
.skip-link {
  position: absolute;
  top: -40px;
  left: 0;
  background: var(--aphi-royal-blue);
  color: var(--aphi-white);
  padding: 8px 16px;
  text-decoration: none;
  font-weight: 600;
  z-index: 100;
}

.skip-link:focus {
  top: 0;
}

/* ============================================
   Typography
   ============================================ */
h1, h2, h3, h4, h5, h6 {
  font-family: var(--font-primary);
  font-weight: 700;
  line-height: 1.2;
  color: var(--aphi-black);
  margin-bottom: var(--spacing-md);
}

h1 {
  font-size: 2.5rem;
  font-weight: 800;
}

h2 {
  font-size: 2rem;
  font-weight: 700;
}

h3 {
  font-size: 1.5rem;
  font-weight: 600;
}

h4 {
  font-size: 1.25rem;
  font-weight: 600;
}

h5 {
  font-size: 1.125rem;
  font-weight: 600;
}

h6 {
  font-size: 1rem;
  font-weight: 600;
}

p {
  margin-bottom: var(--spacing-md);
  color: var(--aphi-dark-gray);
  font-size: 1.0625rem;
  line-height: 1.7;
}

a {
  color: var(--aphi-royal-blue);
  text-decoration: none;
  transition: color var(--transition-fast);
}

a:hover {
  color: var(--aphi-deep-blue);
}

/* ============================================
   Navigation
   ============================================ */
.nav-header {
  background-color: var(--aphi-white);
  border-bottom: 1px solid var(--aphi-light-gray);
  position: sticky;
  top: 0;
  z-index: 1000;
  box-shadow: 0 1px 3px rgba(0, 0, 0, 0.05);
}

.nav-container {
  max-width: 1280px;
  margin: 0 auto;
  padding: var(--spacing-md) var(--spacing-lg);
  display: flex;
  justify-content: space-between;
  align-items: center;
}

.nav-logo {
  display: flex;
  align-items: center;
  gap: var(--spacing-sm);
  text-decoration: none;
  transition: all var(--transition-fast);
}

.nav-logo img {
  height: 40px;
  width: auto;
  transition: transform var(--transition-fast);
}

.nav-logo:hover img {
  transform: scale(1.05);
}

.nav-logo-text {
  font-family: var(--font-heading);
  font-size: 1.5rem;
  font-weight: 700;
  color: var(--aphi-royal-blue);
  letter-spacing: 0.5px;
}

.nav-logo:hover .nav-logo-text {
  color: var(--aphi-deep-blue);
}

.nav-menu {
  display: flex;
  list-style: none;
  gap: var(--spacing-lg);
  align-items: center;
}

/* Navigation Item with Dropdown */
.nav-item {
  position: relative;
}

.nav-link {
  color: var(--aphi-dark-gray);
  font-weight: 500;
  font-size: 0.9375rem;
  padding: var(--spacing-xs) var(--spacing-sm);
  border-radius: 6px;
  transition: all var(--transition-fast);
  display: flex;
  align-items: center;
  gap: 0.25rem;
}

.nav-link:hover,
.nav-link.active {
  color: var(--aphi-royal-blue);
  background-color: var(--aphi-sky-blue);
}

/* Dropdown Arrow */
.nav-link.has-dropdown::after {
  content: '';
  display: inline-block;
  width: 0;
  height: 0;
  margin-left: 0.25rem;
  border-left: 4px solid transparent;
  border-right: 4px solid transparent;
  border-top: 4px solid currentColor;
  transition: transform var(--transition-fast);
}

.nav-item:hover .nav-link.has-dropdown::after {
  transform: rotate(180deg);
}

/* Dropdown Menu */
.nav-dropdown {
  position: absolute;
  top: calc(100% + 0.5rem);
  left: 50%;
  transform: translateX(-50%);
  background: var(--aphi-white);
  border-radius: 8px;
  box-shadow: 0 10px 40px rgba(0, 0, 0, 0.15);
  opacity: 0;
  visibility: hidden;
  transition: all var(--transition-normal);
  min-width: 280px;
  padding: 0.75rem 0;
  z-index: 1000;
}

.nav-item:hover .nav-dropdown {
  opacity: 1;
  visibility: visible;
  top: calc(100% + 0.25rem);
}

/* Dropdown Items */
.nav-dropdown-item {
  display: block;
  padding: 0.75rem 1.5rem;
  color: var(--aphi-dark-gray);
  text-decoration: none;
  transition: all var(--transition-fast);
  border-left: 3px solid transparent;
}

.nav-dropdown-item:hover {
  background-color: var(--aphi-sky-blue);
  color: var(--aphi-royal-blue);
  border-left-color: var(--aphi-royal-blue);
  padding-left: 1.75rem;
}

.nav-dropdown-item-title {
  font-weight: 600;
  font-size: 0.9375rem;
  display: block;
  margin-bottom: 0.25rem;
}

.nav-dropdown-item-desc {
  font-size: 0.8125rem;
  color: var(--aphi-gray);
  line-height: 1.4;
}

.nav-dropdown-divider {
  height: 1px;
  background-color: var(--aphi-light-gray);
  margin: 0.5rem 0;
}

.nav-cta {
  background-color: var(--aphi-royal-blue);
  color: var(--aphi-white) !important;
  padding: var(--spacing-xs) var(--spacing-md);
  border-radius: 6px;
  font-weight: 600;
  transition: all var(--transition-fast);
}

.nav-cta:hover {
  background-color: var(--aphi-deep-blue);
  transform: translateY(-1px);
  box-shadow: 0 4px 12px rgba(0, 71, 171, 0.2);
}

/* Mobile Navigation Toggle */
.nav-toggle {
  display: none;
  background: none;
  border: none;
  cursor: pointer;
  padding: var(--spacing-xs);
}

.nav-toggle span {
  display: block;
  width: 25px;
  height: 3px;
  background-color: var(--aphi-charcoal);
  margin: 5px 0;
  transition: all var(--transition-fast);
}

/* ============================================
   Layout Components
   ============================================ */
.container {
  max-width: 1280px;
  margin: 0 auto;
  padding: 0 var(--spacing-lg);
}

.section {
  padding: var(--spacing-2xl) 0;
}

.section-alt {
  background-color: var(--aphi-off-white);
}

.section-header {
  text-align: center;
  margin-bottom: var(--spacing-xl);
}

.section-title {
  font-size: 2.25rem;
  margin-bottom: var(--spacing-md);
  color: var(--aphi-black);
}

.section-subtitle {
  font-size: 1.125rem;
  color: var(--aphi-gray);
  max-width: 700px;
  margin: 0 auto;
  line-height: 1.7;
}

.section-divider {
  width: 60px;
  height: 4px;
  background-color: var(--aphi-royal-blue);
  margin: 0 auto var(--spacing-md);
  border-radius: 2px;
}

/* ============================================
   Grid Systems
   ============================================ */
.grid {
  display: grid;
  gap: var(--spacing-lg);
}

.grid-2 {
  grid-template-columns: repeat(2, 1fr);
}

.grid-3 {
  grid-template-columns: repeat(3, 1fr);
}

.grid-4 {
  grid-template-columns: repeat(4, 1fr);
}

/* ============================================
   Cards
   ============================================ */
.card {
  background-color: var(--aphi-white);
  border-radius: 12px;
  padding: var(--spacing-lg);
  border: 1px solid var(--aphi-light-gray);
  transition: all var(--transition-normal);
  height: 100%;
}

.card:hover {
  box-shadow: 0 10px 30px rgba(0, 0, 0, 0.1);
  transform: translateY(-4px);
  border-color: var(--aphi-royal-blue);
}

.card-icon {
  width: 48px;
  height: 48px;
  background-color: var(--aphi-sky-blue);
  border-radius: 10px;
  display: flex;
  align-items: center;
  justify-content: center;
  margin-bottom: var(--spacing-md);
  color: var(--aphi-royal-blue);
  font-size: 1.5rem;
  font-weight: 700;
}

.card-title {
  font-size: 1.25rem;
  font-weight: 600;
  margin-bottom: var(--spacing-sm);
  color: var(--aphi-black);
}

.card-description {
  font-size: 1rem;
  color: var(--aphi-gray);
  line-height: 1.6;
  margin-bottom: 0;
}

/* ============================================
   Buttons
   ============================================ */
.btn {
  display: inline-block;
  padding: 0.75rem 1.5rem;
  font-size: 1rem;
  font-weight: 600;
  text-align: center;
  border-radius: 6px;
  border: none;
  cursor: pointer;
  transition: all var(--transition-fast);
  text-decoration: none;
  font-family: var(--font-primary);
}

.btn-primary {
  background-color: var(--aphi-royal-blue);
  color: var(--aphi-white);
}

.btn-primary:hover {
  background-color: var(--aphi-deep-blue);
  color: var(--aphi-white);
  transform: translateY(-2px);
  box-shadow: 0 6px 20px rgba(0, 71, 171, 0.25);
}

.btn-secondary {
  background-color: transparent;
  color: var(--aphi-royal-blue);
  border: 2px solid var(--aphi-royal-blue);
}

.btn-secondary:hover {
  background-color: var(--aphi-royal-blue);
  color: var(--aphi-white);
}

.btn-large {
  padding: 1rem 2rem;
  font-size: 1.125rem;
}

.btn-full-width {
  width: 100%;
}

.btn-hero-secondary {
  background: rgba(255,255,255,0.2);
  border-color: white;
  color: white;
}

.btn-hero-secondary:hover {
  background: rgba(255,255,255,0.3);
  border-color: white;
  color: white;
}

/* ============================================
   Hero Section
   ============================================ */
.hero {
  background: linear-gradient(135deg,
    var(--aphi-deep-blue) 0%,
    var(--aphi-royal-blue) 50%,
    var(--aphi-light-blue) 100%);
  color: var(--aphi-white);
  padding: var(--spacing-2xl) 0;
  min-height: 500px;
  display: flex;
  align-items: center;
  position: relative;
  overflow: hidden;
}

/* Animated Background Elements */
.hero::before {
  content: '';
  position: absolute;
  top: -50%;
  right: -20%;
  width: 100%;
  height: 200%;
  background: radial-gradient(circle,
    rgba(255,255,255,0.1) 0%,
    transparent 70%);
  animation: pulse 8s ease-in-out infinite;
  pointer-events: none;
}

@keyframes pulse {
  0%, 100% {
    opacity: 0.5;
    transform: scale(1);
  }
  50% {
    opacity: 0.8;
    transform: scale(1.1);
  }
}

/* Decorative Blobs */
.hero-decorative {
  position: absolute;
  top: 0;
  left: 0;
  right: 0;
  bottom: 0;
  overflow: hidden;
  z-index: 0;
  opacity: 0.15;
  pointer-events: none;
}

.blob {
  position: absolute;
  border-radius: 50%;
  filter: blur(80px);
  animation: float 20s ease-in-out infinite;
}

.blob-1 {
  width: 400px;
  height: 400px;
  background: rgba(255, 255, 255, 0.3);
  top: -10%;
  right: -10%;
  animation-delay: 0s;
}

.blob-2 {
  width: 300px;
  height: 300px;
  background: rgba(255, 255, 255, 0.2);
  bottom: -10%;
  left: -5%;
  animation-delay: -5s;
}

@keyframes float {
  0%, 100% { transform: translate(0, 0) rotate(0deg); }
  25% { transform: translate(20px, -20px) rotate(5deg); }
  50% { transform: translate(-20px, 20px) rotate(-5deg); }
  75% { transform: translate(20px, 20px) rotate(3deg); }
}

/* Dot Grid Pattern */
.grid-pattern {
  position: absolute;
  top: 0;
  left: 0;
  right: 0;
  bottom: 0;
  background-image: radial-gradient(circle, rgba(255,255,255,0.15) 1px, transparent 1px);
  background-size: 30px 30px;
  opacity: 0.3;
  pointer-events: none;
}

.hero-content {
  max-width: 800px;
}

.hero-title {
  font-size: 3rem;
  font-weight: 800;
  color: var(--aphi-white);
  margin-bottom: var(--spacing-md);
  line-height: 1.1;
}

.hero-subtitle {
  font-size: 1.25rem;
  color: rgba(255, 255, 255, 0.9);
  margin-bottom: var(--spacing-xl);
  line-height: 1.6;
}

.hero-cta {
  display: flex;
  gap: var(--spacing-md);
  flex-wrap: wrap;
}

/* ============================================
   Stats Section
   ============================================ */
.stats-grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(200px, 1fr));
  gap: var(--spacing-lg);
  text-align: center;
}

.stat-item {
  padding: var(--spacing-lg);
}

.stat-number {
  font-size: 2.5rem;
  font-weight: 800;
  color: var(--aphi-royal-blue);
  display: block;
  margin-bottom: var(--spacing-xs);
}

.stat-label {
  font-size: 1rem;
  color: var(--aphi-gray);
  font-weight: 500;
}

/* ============================================
   Feature Highlights
   ============================================ */
.feature-row {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: var(--spacing-xl);
  align-items: center;
  margin-bottom: var(--spacing-2xl);
}

.feature-row:nth-child(even) {
  direction: rtl;
}

.feature-row:nth-child(even) > * {
  direction: ltr;
}

.feature-content h3 {
  font-size: 1.75rem;
  margin-bottom: var(--spacing-md);
}

.feature-image {
  background-color: var(--aphi-light-gray);
  border-radius: 12px;
  aspect-ratio: 16 / 10;
  display: flex;
  align-items: center;
  justify-content: center;
  color: var(--aphi-gray);
}

/* ============================================
   Footer
   ============================================ */
.footer {
  background-color: var(--aphi-charcoal);
  color: var(--aphi-light-gray);
  padding: var(--spacing-2xl) 0 var(--spacing-lg);
}

.footer-content {
  display: grid;
  grid-template-columns: 2fr 1fr 1fr 1fr;
  gap: var(--spacing-xl);
  margin-bottom: var(--spacing-xl);
}

.footer-section h4 {
  color: var(--aphi-white);
  margin-bottom: var(--spacing-md);
  font-size: 1.125rem;
}

.footer-section p,
.footer-section a {
  color: var(--aphi-light-gray);
  font-size: 0.9375rem;
  line-height: 1.8;
}

.footer-section a:hover {
  color: var(--aphi-white);
}

.footer-links {
  list-style: none;
}

.footer-links li {
  margin-bottom: var(--spacing-sm);
}

.footer-bottom {
  border-top: 1px solid rgba(255, 255, 255, 0.1);
  padding-top: var(--spacing-lg);
  text-align: center;
  color: var(--aphi-gray);
  font-size: 0.875rem;
}

/* ============================================
   Responsive Design
   ============================================ */
@media (max-width: 1024px) {
  .grid-4 {
    grid-template-columns: repeat(2, 1fr);
  }

  .footer-content {
    grid-template-columns: 1fr 1fr;
  }

  .feature-row {
    grid-template-columns: 1fr;
  }

  .feature-row:nth-child(even) {
    direction: ltr;
  }
}

@media (max-width: 768px) {
  html {
    font-size: 15px;
  }

  h1 {
    font-size: 2rem;
  }

  h2 {
    font-size: 1.75rem;
  }

  .nav-menu {
    display: none;
    position: absolute;
    top: 100%;
    left: 0;
    right: 0;
    background-color: var(--aphi-white);
    flex-direction: column;
    padding: var(--spacing-md);
    box-shadow: 0 4px 12px rgba(0, 0, 0, 0.1);
    gap: 0;
  }

  .nav-menu.active {
    display: flex;
  }

  .nav-toggle {
    display: block;
  }

  /* Mobile Dropdown Styles */
  .nav-item {
    width: 100%;
  }

  .nav-link {
    width: 100%;
    justify-content: space-between;
  }

  .nav-dropdown {
    position: static;
    transform: none;
    opacity: 1;
    visibility: visible;
    box-shadow: none;
    padding: 0;
    margin-top: 0.5rem;
    border-left: 2px solid var(--aphi-sky-blue);
    background: var(--aphi-off-white);
    display: none;
  }

  .nav-item:hover .nav-dropdown {
    top: auto;
  }

  /* Mobile dropdown toggle */
  .nav-item.dropdown-open .nav-dropdown {
    display: block;
  }

  .nav-dropdown-item {
    padding: 0.75rem 1rem;
  }

  .grid-2,
  .grid-3,
  .grid-4 {
    grid-template-columns: 1fr;
  }

  .hero-title {
    font-size: 2rem;
  }

  .hero-subtitle {
    font-size: 1.125rem;
  }

  .footer-content {
    grid-template-columns: 1fr;
  }

  .section {
    padding: var(--spacing-xl) 0;
  }
}

/* ============================================
   Utility Classes
   ============================================ */
.text-center {
  text-align: center;
}

.text-left {
  text-align: left;
}

.text-right {
  text-align: right;
}

.mb-0 {
  margin-bottom: 0;
}

.mb-sm {
  margin-bottom: var(--spacing-sm);
}

.mb-md {
  margin-bottom: var(--spacing-md);
}

.mb-lg {
  margin-bottom: var(--spacing-lg);
}

.mb-xl {
  margin-bottom: var(--spacing-xl);
}

.mt-0 {
  margin-top: 0;
}

.mt-sm {
  margin-top: var(--spacing-sm);
}

.mt-md {
  margin-top: var(--spacing-md);
}

.mt-lg {
  margin-top: var(--spacing-lg);
}

.mt-xl {
  margin-top: var(--spacing-xl);
}

.badge {
  display: inline-block;
  padding: 0.25rem 0.75rem;
  background-color: var(--aphi-sky-blue);
  color: var(--aphi-royal-blue);
  border-radius: 20px;
  font-size: 0.875rem;
  font-weight: 600;
  text-transform: uppercase;
  letter-spacing: 0.5px;
}

.highlight {
  color: var(--aphi-royal-blue);
  font-weight: 600;
}

/* ============================================
   Callouts (Notes / Limitations / Alerts)
   ============================================ */
.callout {
  border-left: 5px solid var(--aphi-royal-blue);
  background: var(--aphi-off-white);
  padding: var(--spacing-md) var(--spacing-lg);
  border-radius: 6px;
  margin: var(--spacing-xl) 0;
}
.callout h4 { margin-top: 0; margin-bottom: var(--spacing-sm); }
.callout.limitations { border-color: var(--aphi-orange); }
.callout.limitations h4 { color: var(--aphi-orange); }
.callout.danger { border-color: var(--aphi-red); }
.callout.success { border-color: var(--aphi-green); }

/* Additional utilities */
.hero-cta.center { justify-content: center; }
.gap-2xl { gap: var(--spacing-2xl); }
.stage-orange { background: var(--aphi-orange) !important; }
.stage-green { background: var(--aphi-green) !important; }
.text-gray { color: var(--aphi-gray); }
.font-sm { font-size: 0.875rem; }

/* Margin Left Utilities */
.ml-sm { margin-left: var(--spacing-sm); }
.ml-md { margin-left: var(--spacing-md); }
.ml-lg { margin-left: var(--spacing-lg); }

/* Text Color Utilities */
.text-dark { color: var(--aphi-dark-gray); }

/* Reference List Styles */
.reference-item { display: flex; margin-bottom: var(--spacing-lg); padding-bottom: var(--spacing-lg); border-bottom: 1px solid var(--aphi-light-gray); }
.reference-item:last-child { border-bottom: none; }
.reference-number { display:inline-block; width:40px; height:40px; background-color: var(--aphi-royal-blue); color:#fff; border-radius:50%; text-align:center; line-height:40px; font-weight:700; margin-right: var(--spacing-md); flex-shrink:0; }
.reference-content { flex:1; }
.reference-title { font-weight:600; color: var(--aphi-black); margin-bottom: var(--spacing-xs); }
.reference-citation { color: var(--aphi-dark-gray); font-style: italic; margin-bottom: var(--spacing-xs); line-height:1.6; }
.reference-link { color: var(--aphi-royal-blue); font-size:0.9375rem; }
.reference-link:hover { text-decoration: underline; }
.reference-category { background-color: var(--aphi-sky-blue); color: var(--aphi-royal-blue); padding:0.25rem 0.75rem; border-radius:12px; font-size:0.8125rem; font-weight:600; text-transform:uppercase; letter-spacing:0.5px; display:inline-block; margin-bottom: var(--spacing-sm); }
.toc { background-color: var(--aphi-off-white); padding: var(--spacing-lg); border-radius:8px; margin-bottom: var(--spacing-xl); }
.toc h3 { margin-bottom: var(--spacing-md); font-size:1.125rem; }
.toc ul { list-style:none; padding-left:0; }
.toc li { margin-bottom: var(--spacing-xs); }
.toc a { color: var(--aphi-royal-blue); transition: color var(--transition-fast); }
.toc a:hover { color: var(--aphi-deep-blue); text-decoration: underline; }

/* ============================================
  Model Cards (Transparency) Styles
  ============================================ */
.model-grid { display: grid; gap: 2rem; margin-top: 2rem; }
@media (min-width: 1000px) { .model-grid { grid-template-columns: repeat(3, 1fr); } }
.stage { font-size: 0.65rem; background: var(--aphi-light-blue); color: #fff; padding: 2px 6px; border-radius: 10px; font-weight: 600; letter-spacing: .5px; }
.performance-table { width:100%; border-collapse: collapse; font-size: .8rem; margin-top: .5rem; }
.performance-table th, .performance-table td { border:1px solid var(--aphi-light-gray); padding:4px 6px; text-align:left; }
details summary { cursor:pointer; font-weight:600; }
details { margin-top: .75rem; }

/* ============================================
   PREMIUM DESIGN ENHANCEMENTS
   ============================================ */

/* Enhanced Card Shadows & Hover Effects */
.card {
  box-shadow: 0 1px 3px rgba(0, 0, 0, 0.06);
  transition: all 0.3s cubic-bezier(0.4, 0, 0.2, 1);
}

.card:hover {
  box-shadow:
    0 4px 20px rgba(0, 71, 171, 0.08),
    0 1px 3px rgba(0, 0, 0, 0.06);
  transform: translateY(-4px);
}

/* Elevation System */
.elevation-1 { box-shadow: 0 1px 3px rgba(0,0,0,0.12), 0 1px 2px rgba(0,0,0,0.06); }
.elevation-2 { box-shadow: 0 3px 6px rgba(0,0,0,0.12), 0 2px 4px rgba(0,0,0,0.08); }
.elevation-3 { box-shadow: 0 10px 40px rgba(0,0,0,0.15), 0 3px 6px rgba(0,0,0,0.10); }

/* Sophisticated Button Variants */
.btn-ghost {
  background: transparent;
  border: 2px solid var(--aphi-royal-blue);
  color: var(--aphi-royal-blue);
  padding: 0.75rem 1.5rem;
  border-radius: 8px;
  font-weight: 600;
  transition: all 0.3s ease;
  text-decoration: none;
  display: inline-block;
}

.btn-ghost:hover {
  background: var(--aphi-royal-blue);
  color: white;
  transform: translateY(-2px);
  box-shadow: 0 8px 20px rgba(0, 71, 171, 0.25);
}

.btn-pill {
  border-radius: 50px;
  padding: 0.875rem 2rem;
  background: linear-gradient(135deg, var(--aphi-royal-blue), var(--aphi-light-blue));
  color: white;
  border: none;
  font-weight: 600;
  transition: all 0.3s ease;
  text-decoration: none;
  display: inline-block;
}

.btn-pill:hover {
  box-shadow: 0 12px 28px rgba(0, 71, 171, 0.3);
  transform: translateY(-3px);
}

/* Button with Icon */
.btn-icon {
  display: inline-flex;
  align-items: center;
  gap: 0.5rem;
}

.btn-icon svg {
  width: 18px;
  height: 18px;
  transition: transform 0.3s ease;
}

.btn-icon:hover svg {
  transform: translateX(4px);
}

/* Button Micro-Interaction (Ripple Effect) */
.btn {
  position: relative;
  overflow: hidden;
}

.btn::before {
  content: '';
  position: absolute;
  top: 50%;
  left: 50%;
  width: 0;
  height: 0;
  border-radius: 50%;
  background: rgba(255, 255, 255, 0.3);
  transform: translate(-50%, -50%);
  transition: width 0.6s, height 0.6s;
}

.btn:hover::before {
  width: 300px;
  height: 300px;
}

/* Enhanced Typography */
.display-heading {
  font-size: 3rem;
  font-weight: 800;
  line-height: 1.1;
  letter-spacing: -0.02em;
  background: linear-gradient(135deg, var(--aphi-deep-blue), var(--aphi-light-blue));
  -webkit-background-clip: text;
  -webkit-text-fill-color: transparent;
  background-clip: text;
}

.eyebrow {
  font-size: 0.75rem;
  font-weight: 600;
  letter-spacing: 1.5px;
  text-transform: uppercase;
  color: var(--aphi-royal-blue);
  margin-bottom: 0.5rem;
  display: block;
}

/* Enhanced Focus States */
*:focus-visible {
  outline: 3px solid var(--aphi-light-blue);
  outline-offset: 3px;
  border-radius: 4px;
}

.btn:focus-visible {
  outline: 3px solid var(--aphi-light-blue);
  outline-offset: 3px;
  box-shadow:
    0 0 0 3px white,
    0 0 0 6px var(--aphi-light-blue);
}

.nav-link:focus-visible {
  outline: 2px dotted var(--aphi-royal-blue);
  outline-offset: 4px;
}

.card:focus-within {
  box-shadow:
    0 0 0 3px var(--aphi-sky-blue),
    0 10px 40px rgba(0, 71, 171, 0.15);
  transform: translateY(-2px);
}

/* Animated Statistics */
.stat-number {
  font-size: 3rem;
  font-weight: 800;
  background: linear-gradient(135deg, var(--aphi-royal-blue), var(--aphi-light-blue));
  -webkit-background-clip: text;
  -webkit-text-fill-color: transparent;
  background-clip: text;
  line-height: 1;
}

/* Fade-in Animation on Scroll */
@keyframes fadeInUp {
  from {
    opacity: 0;
    transform: translateY(30px);
  }
  to {
    opacity: 1;
    transform: translateY(0);
  }
}

.animate-on-scroll {
  opacity: 0;
  animation: fadeInUp 0.8s ease-out forwards;
}

.animate-on-scroll:nth-child(1) { animation-delay: 0.1s; }
.animate-on-scroll:nth-child(2) { animation-delay: 0.2s; }
.animate-on-scroll:nth-child(3) { animation-delay: 0.3s; }
.animate-on-scroll:nth-child(4) { animation-delay: 0.4s; }

/* Section Label (Academic Style) */
.section-label {
  font-size: 0.75rem;
  font-weight: 600;
  letter-spacing: 1.5px;
  text-transform: uppercase;
  color: var(--aphi-royal-blue);
  margin-bottom: 0.5rem;
  display: block;
}

/* Gradient Section Backgrounds */
.section-gradient-subtle {
  background: linear-gradient(180deg,
    var(--aphi-off-white) 0%,
    white 100%);
}

/* ============================================
  Privacy Page Styles (migrated from inline)
  ============================================ */
.privacy-principle { background-color: var(--aphi-white); border-left: 4px solid var(--aphi-royal-blue); padding: var(--spacing-lg); margin-bottom: var(--spacing-lg); border-radius: 6px; box-shadow: 0 2px 8px rgba(0,0,0,0.05); }
.privacy-principle h3 { color: var(--aphi-royal-blue); margin-bottom: var(--spacing-sm); display:flex; align-items:center; gap: var(--spacing-sm); }
.principle-icon { width:32px; height:32px; background-color: var(--aphi-sky-blue); border-radius:50%; display:flex; align-items:center; justify-content:center; flex-shrink:0; }
.technical-detail { background-color: var(--aphi-off-white); padding: var(--spacing-md); border-radius:6px; margin-top: var(--spacing-sm); font-family: 'Courier New', monospace; font-size:0.875rem; }
.data-flow { background: linear-gradient(135deg, #E3F2FD 0%, #F3E5F5 100%); padding: var(--spacing-xl); border-radius:12px; margin: var(--spacing-xl) 0; }
.flow-step { display:flex; align-items:start; margin-bottom: var(--spacing-lg); gap: var(--spacing-md); }
.flow-number { background-color: var(--aphi-royal-blue); color:#fff; width:40px; height:40px; border-radius:50%; display:flex; align-items:center; justify-content:center; font-weight:700; flex-shrink:0; }
.compliance-badge { display:inline-flex; align-items:center; padding:0.5rem 1rem; background-color:#D1FAE5; border:2px solid #10B981; border-radius:8px; font-weight:600; color:#065F46; margin-right: var(--spacing-md); margin-bottom: var(--spacing-sm); }
.check-icon { width:20px; height:20px; margin-right:0.5rem; }

/* ============================================
  Additional Spacing / Utility Enhancements
  ============================================ */
.p-xl { padding: var(--spacing-xl); }
.text-royal { color: var(--aphi-royal-blue); }

/* ============================================
  Contact Form Styles
  ============================================ */
.contact-form-container {
  max-width: 700px;
  margin: 0 auto;
}

.form-group {
  margin-bottom: var(--spacing-lg);
}

.form-group label {
  display: block;
  margin-bottom: var(--spacing-xs);
  font-weight: 600;
  color: var(--aphi-charcoal);
}

.form-group input,
.form-group textarea,
.form-group select {
  width: 100%;
  padding: 0.75rem 1rem;
  border: 2px solid var(--aphi-light-gray);
  border-radius: 6px;
  font-size: 1rem;
  font-family: var(--font-primary);
  transition: border-color var(--transition-fast);
  background-color: var(--aphi-white);
}

.form-group input:focus,
.form-group textarea:focus,
.form-group select:focus {
  outline: none;
  border-color: var(--aphi-royal-blue);
}

.form-group textarea {
  min-height: 150px;
  resize: vertical;
}

.form-required {
  color: var(--aphi-red);
}

.contact-info-grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(250px, 1fr));
  gap: var(--spacing-lg);
  margin-top: var(--spacing-xl);
}

.contact-info-item {
  text-align: center;
  padding: var(--spacing-lg);
}

.contact-icon {
  width: 60px;
  height: 60px;
  background-color: var(--aphi-sky-blue);
  border-radius: 50%;
  display: flex;
  align-items: center;
  justify-content: center;
  margin: 0 auto var(--spacing-md);
  color: var(--aphi-royal-blue);
  font-size: 1.5rem;
}

/* Form Validation Feedback */
.form-feedback {
  margin-top: var(--spacing-md);
  padding: var(--spacing-md);
  border-radius: 6px;
  font-weight: 600;
}

.form-feedback.success {
  background-color: #D1FAE5;
  color: #065F46;
  border: 2px solid var(--aphi-green);
}

.form-feedback.error {
  background-color: #FEE2E2;
  color: #991B1B;
  border: 2px solid var(--aphi-red);
}